The present invention relates to a data processing method and a data processing apparatus as well as a data processing system for accessing data stored in the apparatus or in an external apparatus.
Along with the recent development in portable data processing apparatus, there are increasing cases where a person carries the apparatus outside a company with important information related to the company stored in the memory of the apparatus or in a secondary memory device. Also, data exchange between a company and the apparatus outside the company is performed via a modem or the like.
In such portable data processing apparatus, data is protected by requiring input of a password at the time of turning on power of the apparatus or at the time of opening a specific page of data. The purpose of such password input is to prevent other people from accessing confidential information or using it without permission in a normal situation, or preventing access when the portable data processing apparatus is lost by chance.
Furthermore, today, since communication lines are widely established, a password is basically used as a key to obtain data access permission to access remote data or data access operation among client servers.
Meanwhile, lately, for the purpose of automobile navigation, GPS (Global Positioning System) which is capable of calculating the position of an automobile by receiving data from orbital satellites is rapidly introduced to the market. Since its theory is well-known, details will not be provided herein; however briefly, data with respect to latitude, longitude, height, and radiated time of radio wave sent from twenty-four satellites circulating the earth, is received from at least four of the satellites, and correct position data of oneself or time data can be obtained. Since accurate time can be obtained by virtue of the above, this theory tends to be adopted not only to a portable apparatus but also to a non-portable desktop-type apparatus. For a portable apparatus, the GPS is expected to be applied not only to an automobile navigation system but also to a general PDA (Personal Digital Assistance: a small-size personal data processing terminal) or a subnotebook-type personal computer or the like by utilizing a PCMCIA card or the like.
As set forth above, a password is generally utilized as a key to data access permission. However, since a password is merely a combination of numbers and characters, it is possible for a hacker to generate the password by obtaining a number of possible sequences of characters. Moreover, a portable apparatus often utilizes a simple password with small number of digits, thus such password can be easily determined. Moreover, remote access operation is also problematic since confidential data is protected only by such password.